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<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>平行光的阴影，辅助对象</title>
    <style>
      body {
        margin: 0;
        overflow: hidden;
        /* 隐藏body窗口区域滚动条 */
      }
    </style>
    <!--引入three.js三维引擎-->
    <!-- <script src="http://www.yanhuangxueyuan.com/versions/threejsR92/build/three.js"></script> -->
    <!-- <script src="http://www.yanhuangxueyuan.com/threejs/build/three.js"></script> -->
    <!-- Three.js-master 包示例中的用法 examples/js/controls/OrbitControls.js  版本要匹配-->
    <script src="http://www.yanhuangxueyuan.com/3D/example/three.min.js"></script>
    <script src="../../util/OrbitControls.js"></script>
  </head>
  <body>
    <script type="module">
      // import { RAFTime } from "../../util/index.js";
      /**
       * 创建场景对象Scene
       */
      var scene = new THREE.Scene();

      /**
       * 辅助坐标系 参数250表示坐标系大小，可以根据场景大小去设置
       */
      var axisHelper = new THREE.AxisHelper(1000);
      scene.add(axisHelper);

      var geometry = new THREE.BoxGeometry(40, 100, 40);
      var material = new THREE.MeshLambertMaterial({
        color: 0x0000ff,
      });
      var mesh = new THREE.Mesh(geometry, material);
      // mesh.position.set(0,0,0)
      // 设置产生投影的网格模型
      mesh.castShadow = true;
      scene.add(mesh);

      //创建一个平面几何体作为投影面
      var planeGeometry = new THREE.PlaneGeometry(300, 200);
      var planeMaterial = new THREE.MeshLambertMaterial({
        color: 0x999999,
      });
      // 平面网格模型作为投影面
      var planeMesh = new THREE.Mesh(planeGeometry, planeMaterial);
      planeMesh.rotateX(-Math.PI / 2); //旋转网格模型
      planeMesh.position.y = -100; //设置网格模型y坐标
      // 设置接收阴影的投影面
      planeMesh.receiveShadow = true;
      scene.add(planeMesh); //网格模型添加到场景中

      // 平行光
      var directionalLight = new THREE.DirectionalLight(0xffffff, 1);
      // 平行光辅助对象
      const directionalLightHelper = new THREE.DirectionalLightHelper(
        directionalLight,
        10
      );
      scene.add(directionalLightHelper);
      // 设置光源位置
      directionalLight.position.set(45, 75, 30);
      scene.add(directionalLight);
      // 设置用于计算阴影的光源对象
      directionalLight.castShadow = true;
      // 设置计算阴影的区域，最好刚好紧密包围在对象周围
      // 计算阴影的区域过大：模糊  过小：看不到或显示不完整
      directionalLight.shadow.camera.near = 0.5;
      directionalLight.shadow.camera.far = 300;
      directionalLight.shadow.camera.left = -100;
      directionalLight.shadow.camera.right = 100;
      directionalLight.shadow.camera.top = 200;
      directionalLight.shadow.camera.bottom = -100;
      // 设置mapSize属性可以使阴影更清晰，不那么模糊
      directionalLight.shadow.mapSize.set(1024, 1024);
      console.log(directionalLight.shadow.camera);

      // // 聚光光源
      // var spotLight = new THREE.SpotLight(0xffffff);
      // // 聚光源辅助对象，可视化聚光源
      // const spotLightHelper = new THREE.SpotLightHelper(spotLight, 0xffffff);
      // scene.add(spotLightHelper);
      // // 设置聚光光源位置
      // spotLight.position.set(40, 100, 40);
      // // 设置聚光光源发散角度
      // spotLight.angle = Math.PI / 2;
      // scene.add(spotLight); //光对象添加到scene场景中
      // // 设置用于计算阴影的光源对象
      // spotLight.castShadow = true;
      // // 设置计算阴影的区域，注意包裹对象的周围
      // spotLight.shadow.camera.near = 1;
      // spotLight.shadow.camera.far = 300;
      // spotLight.shadow.camera.fov = 20;

      // //环境光
      // var ambient = new THREE.AmbientLight(0x000000);
      // scene.add(ambient);

      /**
       * 相机设置
       */
      var width = window.innerWidth; //窗口宽度
      var height = window.innerHeight; //窗口高度
      var k = width / height; //窗口宽高比
      var s = 100; //三维场景显示范围控制系数，系数越大，显示的范围越大
      //创建相机对象
      var camera = new THREE.OrthographicCamera(-s * k, s * k, s, -s, 1, 1000);
      camera.position.set(60, 60, 60); //设置相机位置
      camera.lookAt(scene.position); //设置相机方向(指向的场景对象)

      /**
       * 创建渲染器对象
       */
      var renderer = new THREE.WebGLRenderer();
      renderer.setSize(width, height); //设置渲染区域尺寸
      renderer.setClearColor(0xb9d3ff, 1); //设置背景颜色
      // 设置渲染器，允许光源阴影渲染
      renderer.shadowMap.enabled = true;
      document.body.appendChild(renderer.domElement); //body元素中插入canvas对象

      // 监听鼠标、键盘事件，实现 旋转/缩放/平移
      function render() {
        renderer.render(scene, camera); //执行渲染操作
      }
      // 启动渲染
      render();
      render();
      // 创建，轨迹控件
      var controls = new THREE.OrbitControls(camera, renderer.domElement);
      // 监听鼠标、键盘事件
      controls.addEventListener("change", render);
    </script>
  </body>
</html>
